Paedophryne amauensis
Paratype of Paedophryne amauensis (LSUMZ 95004).png
Paratype of Paedophryne amauensis (LSUMZ 95004) on a U.S. dime (diameter 18 mm)[1]
Scientific classification edit
Kingdom: Animalia
Phylum: Chordata
Class: Amphibia
Order: Anura
Family: Microhylidae
Genus: Paedophryne
Species:
P. amauensis
Binomial name
Paedophryne amauensis
Rittmeyer et al., 2012[3]
Synonyms[4]

Asterophrys amanuensis — Dubois et al., 2021

Paedophryne amauensis is a species of microhylid frog endemic to eastern Papua New Guinea.[2][4] At 7.7 mm (0.30 in) in snout-to-vent length, it is considered the world's smallest known vertebrate.[3][5]

The species was listed in the Top 10 New Species 2013 by the International Institute for Species Exploration for discoveries made during 2012.[6][7][8]

Discovery

The frog species was discovered in August 2009 by Louisiana State University herpetologist Christopher Austin and his PhD student Eric Rittmeyer while on an expedition to explore the biodiversity of Papua New Guinea.[9] The new species was found near Amau village in the Central Province, from which its specific name is derived.[3] The discovery was published in the peer-reviewed scientific journal PLOS One in January 2012.[3]

Because the frogs have calls that resemble those made by insects and are camouflaged among leaves on the forest floor, Paedophryne amauensis had been difficult to detect. While recording nocturnal frog calls in the forest, Austin and Rittmeyer used triangulation to identify the source of an unknown animal and discovered the frogs by scooping up handfuls of leaf litter and putting it into plastic bags where they spotted the tiny frog hopping around.[1]

A relative comparison of the world's smallest frogs; behind them is a US dime, which is 17.9 mm in diameter, for scale
A relative comparison of the world's smallest frogs; behind them is a US dime, which is 17.9 mm in diameter, for scale

Characteristics

An X-ray image of a Paedophryne amauensis paratype
An X-ray image of a Paedophryne amauensis paratype

P. amauensis, attaining an average body size of only 7.7 millimetres (0.30 in),[3] is 0.2 millimetres (0.0079 in) smaller than the previous record-holder as the world's smallest vertebrate, a species of cyprinid fish (Paedocypris progenetica; 7.9 mm [0.31 in]) from Indonesia and a species of goby fish (Schindleria brevipinguis; 7.7 mm [0.30 in]) from Australia.[10][11]

The frog lives on land and its life cycle does not include a tadpole stage.[10] Instead, members of this species hatch as 'hoppers': miniatures of the adults.[9] The skeleton is reduced and there are only seven presacral vertebrae present.[3] They are capable of jumping thirty times their body length. The frog is crepuscular and feeds on small invertebrates. Males call for mates with a series of very high-pitched insect-like peeps at a frequency of 8400–9400 Hz.[3]

Habitat

P. amauensis occurs in tropical wet lowland and hill forest at elevations of 177–800 m (581–2,625 ft) above sea level.[2] Due to having a high surface to volume ratio, the Paedophryne amauensis are subject to water-loss and dependent on the high-moisture content of leaf litter.[3] Similar to all species of Paedophryne known so far, members of Paedophryne amauensis live in the leaf litter on the floors of tropical forests.[3]

Conservation

P. amauensis is known from its type locality near Amau village (Central Province) and from the Variarata National Park (National Capital District), both in eastern Papua New Guinea. It is likely to have a much wider range. It is very abundant locally. As large areas of suitable habitat remain, this species is not considered to be threatened at present.[2]

References

  1. ^ a b Black, Richard (11 January 2012). "World's smallest frog discovered". BBC News. Retrieved 12 January 2012.
  2. ^ a b c d IUCN SSC Amphibian Specialist Group. (2020). "Paedophryne amauensis". IUCN Red List of Threatened Species. 2020: e.T76317540A76317832. doi:10.2305/IUCN.UK.2020-3.RLTS.T76317540A76317832.en. Retrieved 10 March 2022.
  3. ^ a b c d e f g h i Rittmeyer, Eric N.; Allison, Allen; Gründler, Michael C.; Thompson, Derrick K.; Austin, Christopher C. (2012). "Ecological guild evolution and the discovery of the world's smallest vertebrate". PLoS ONE. 7 (1): e29797. Bibcode:2012PLoSO...729797R. doi:10.1371/journal.pone.0029797. PMC 3256195. PMID 22253785. (See also Ecological guild.)
  4. ^ a b Frost, Darrel R. (2022). "Paedophryne amauensis Rittmeyer, Allison, Gründler, Thompson, and Austin, 2012". Amphibian Species of the World: an Online Reference. Version 6.1. American Museum of Natural History. doi:10.5531/db.vz.0001. Retrieved 10 March 2022.
  5. ^ "World's tiniest frogs found in Papua New Guinea". The Australian. 12 January 2012. Retrieved 11 January 2012.
  6. ^ Newswise (22 May 2013). "Scientists Announce Top 10 New Species". Arizona State University College of Liberal Arts and Sciences. Newswise, Inc. Retrieved 2013-05-23.
  7. ^ Arizona State University College of Liberal Arts and Sciences (22 May 2013). "Top 10 new species of 2012". ScienceDaily. ScienceDaily, LLC. Retrieved 2013-05-23.
  8. ^ Varma S (23 May 2013). "Amazing top 10 new species include glowing cockroach, tiniest vertebrate and new monkey". The Times of India. Bennett, Coleman & Co. Ltd. Retrieved 2013-05-24.
  9. ^ a b "Tiny frog claimed as world's smallest vertebrate". The Guardian. 12 January 2012. Retrieved 12 January 2012.
  10. ^ a b "World's smallest creature with a vertebrate named". The Daily Telegraph. 12 January 2012. Archived from the original on 12 January 2012. Retrieved 12 January 2012.
  11. ^ "Hallan en Papúa Nueva Guinea a las ranas más pequeñas del mundo" (in Spanish). eluniverso.com. 11 January 2012. Retrieved 12 January 2012.